Elastic has been used extensively in disposable articles such as diapers to create a more comfortable and secure fit, being used primarily along the legs and the waist. An example of a specific design of a waist area elastic is taught in U.S. Patent Application. No 2002/0165516, by Datta et al., which teaches a disposable diaper with a stretchable outer cover, wherein the stretchable outer cover can be configured to provide zones with different levels of level of elongation when subjected to a tensile force.
U.S. Pat. No. 6,456,073, to Morman et al. teaches a stretchable nonwoven web, or laminate of a stretchable nonwoven web and an elastic sheet that is treated with a plurality of bond lines in one or more regions thereof to provide controlled stretching properties. The use of the bond lines reduces the stretchability of the material in the region of the bond lines. This elastic can be used in various regions of a disposable article such as a diaper.
U.S. Pat. No. 6,200,299 to Y. Heki, teaches a disposable diaper with ear parts capable of distributing applied tensile forces around the waist and around the legs to prevent leakage. The elastic distributes forces but provides uneven tension along its length
U.S. Pat. No. 6,336,922 to Van Gompel et al. teaches an absorbent article which includes a fit panel located in the waist region and extending laterally beyond the side edges of the chassis of the article. The fit panel may include a center bridge panel and a pair of laterally opposed side panels wherein the bridge panel and the side panels provide individual zones of elasticity across the width of the fit panel which have different elastic properties.
U.S. Pat. No. 6,264,639 and U.S. Pat. No. 5,938,652, both to B. A. Sauer, teaches an absorbent article, like a diaper, with a waist flap which includes a central zone and a pair of laterally opposed side zones which extend laterally outward from the central zone to the side edges of the absorbent article. Also taught is that the waist flap may include two or more different materials which may be joined together or otherwise arranged to provide different portions of the waist flap with different characteristic or properties, such as different elastic properties.
U.S. Pat. No. 6,132,411, issued to Huber, et. al., teaches absorbent articles, such as diapers, that have a side panel that have a low extension force leg zone and a high extension force waist zone to improve the overall fit of the article as well as reduce red marking on the wearer's skin.
U.S. Pat. No. 5,685,873 to M. A. Bruemmer, teaches a disposable diaper which includes a pair of differentially stretchable ear members which comprise a stretchable inner ear portion and a stretchable outer ear portion wherein these portions of the ears have different stretch characteristics. One method taught to achieve this is to shape the ears with converging tapered sides. Another way to achieve this in non-tapering ears is to use two different stretchable materials having different stretch characteristic. Also taught is using a single material and modifying the stretch characteristics in an area by using bonding lines or points as taught in U.S. Pat. No. 6,456,073 discussed above.
U.S. Pat. No. 5,496,298 to Kuepper et. al. teaches an elastomeric ear suitable for use on a disposable diaper. The elastomeric ear is formed from an elastomeric material which defines a proximal edge, a distal edge, a first connecting edge and a second connecting edge. The first and second connecting edges connect the proximal and distal edges. The second connecting edge is non-parallel to the first connecting edge, and the proximal edge is longer than the distal edge.
U.S. Pat. No. 5,464,401 to Hasse et. al. teaches a unitary disposable garment, such as a disposable training pant, having a high degree of stretch in the cross-machine direction and fitting a broad range of wearer sizes. The chassis from which the garment is manufactured, has four elasticized ear flaps, each ear flap is elasticized by securing an elastomeric element thereto and mechanically stretching the ear flap and the elastomeric element such that the ear flap is elastically extensible in the direction of initial stretching. It is also taught that the elasticized ear flaps may also be provided with differential extensibility along the longitudinal axis when stretched in the lateral direction. It is also taught that this differential extensibility can be achieved in a number of different ways, including that the ear flaps can have multiple combined elastomeric materials, multiple configurations for the elastomeric materials, or the extension properties of the elastomeric material or materials making up the elasticized ear flap may be non-uniform.
U.S. Pat. No. 5,156,793 to Buell et. al. teaches a “zero strain” stretch laminate web exhibiting a non-uniform degree of elasticity, as measured in the direction of web stretching at various points along an axis oriented substantially perpendicular to the direction of web stretching.